


Sleepover in Underfell

by kittyhittyrh



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell (Undertale), Bad Puns, Drinking, Humans, Jealous Underfell Sans, M/M, Magic, Mild Sexual Content, Science Sans/Underfell Sans (Undertale), Scifell - Freeform, Staying in another Universe has lasting effects on the Soul, Underfell Sans (Undertale), Underverse, ink sans - Freeform, science sans
Language: English
Status: Completed
Published: 2020-06-25
Updated: 2020-06-25
Packaged: 2021-03-04 01:01:06
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 2,206
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24904978
Author URL: https://archiveofourown.org/users/kittyhittyrh/pseuds/kittyhittyrh
Summary: Sci's feelings for Edge are obviously to everyone but Edge that is until he decides to show up in Underfell for a week's long sleepover. Edge realizes he may have feelings for the nerd as well.
Relationships: Sans/Sans (Undertale)
Kudos: 28
Collections: Incantale





	Sleepover in Underfell

This was a mistake. A huge fucking mistake. Edge should have made Sci leave the second he saw him. The nerd had shown up earlier that day. He had no care for the fit his brother would throw or the fact that his universe was still dangerous despite it's Frisk's help. Fell would get over it and Sci could defend himself if needed, that’s if Edge didn’t kill the person first.  
No, all that was fine. The problem was now. Sci had convinced Edge to let him sleep in his room. He was asleep and clinging to Edge. Not just clinging but using him as a fucking pillow. Really he should have expected this. Sci was just a nicer, possibly smarter, Edge. When Edge was comfortable he’d do some weird shit in his sleep. Why wouldn’t Sci?  
I know what you’re thinking. Edge, dude, you’re a Sans. Just go to sleep.   
He’d love to just fall asleep. Remember that whole using him as a pillow thing? Yeah not just his head. Try half his body. Which wouldn’t be that bad either if Sci’s fucking knee wasn’t right against his crotch.  
He mumbled in his sleep, giving a small shift. Edge bit his lip as he felt the friction. That really shouldn’t feel good. They were the same person.  
He shifted again, Edge struggled to not make a sound.   
This was going to be a long week.  
~~~~  
The clink of glass being set down heavily against wood startled Edge out of his daze.   
Three nights of the same thing and he’d gotten no sleep. His usual naps not doing anything to help. They weren’t filled with the best images, mostly Sci below him- He should stop thinking about this right now. Not the time or place.  
Sci had convinced him to take him out today. Edge had taken him to Grillby’s since it was the place least likely for someone to try to slaughter him. And this is not a date, even if it was all going on his tab.  
Sci looked at Edge, his eyes weary, “You don’t look so good. Do you want to go back to the house?”   
“Nah, I’ll be fine when I get something in my system.”  
“Right,” He didn’t sound convinced.   
He took a bite of the burger he’d ordered, an excessive amount of ketchup dripping out.  
Edge looked down at his fries then smothered them in mustard.  
They ate in relative silence aside from a joke from Sci every so often.  
Everything was going well until one of the other usual patrons, Edge didn’t remember his name, came up to the bar. He ordered his drink.  
“Hey, Sans.”   
Both Sci and Edge looked over at him.  
“Uh, who’s yer friend? Didn’t even know ya had any. Wow you guys kinda look alike.”  
Not everyone knew about alternate universes.  
“He’s uh.. My cousin.”   
“I’m.. Sci.” That's what everyone called him anyway so it worked.  
“Oh. Visiting? Heh. Sorry you're stuck with this loser. Staying with him and that royal guardsmen must be hell.”   
People shit talked on Fell and Edge all the time. Of course never in front of Fell.  
“I don’t know what you're talking about E- Sans has been very-” Edge kicked him under the table. “Ow!”  
“Wow that foot of yours' acting up again? Doc told ya not to walk on it.”  
Sci glared at him, “Well I’m sorry I wanted to spend time with my cousin.” He seemed really unhappy to call Edge that.  
“Welp, there's my drink. Hope to see ya around, Cutie. Bye Sans.” He gave UF! Grillby the money for his drink and went back to the table with his friends.   
“Are you okay?” Sci asked, taking a drink of ketchup.   
“Why?”   
“You looked ready to kill him for a second there,” He stole one of the last fries Edge had.  
“Get your own,” Edge pulled the plate back, “And I didn’t.”  
“You sure about that, Cous,” he ate the fry, his face scrunching a bit, “Eh, keep em’ that's too much mustard.” He shook his ketchup bottle, before taking another drink from it.  
Edge rolled his eyes and finished his beer, “Hey, Grillbz! Bring me another drink!”   
~~~~  
Sci lead Edge up the stairs. He’d have taken a shortcut but he wasn’t exactly concentrating at the moment.   
Seriously it wasn’t even four in the afternoon and Edge was drunk.  
“Not putting all your weight on me would be nice,” Sci grumbled, Edge let out a chuckle.  
“Sci, Buddy, ya gotta lighten up a bit, you're startin’ ta sound like my bro.”  
Sci snorted, he really must be gone if he was comparing him with Fell.  
“I disagree, if he was there he would have left your drunken ass…”   
“Touchy~” He almost sounded like he was purring.  
They finally reached the landing, Edge tripped a little over the step.   
After getting Edge to his room, Sci practically dropped him on the bed.  
“I’ll get you some water; with how much you drank you’re bound to be dehydrated later.”  
“Nah, stay here,” Edge grabbed Sci’s hand and pulled him down.   
Sci yelped, his glasses gone askew, “Edge, l-let go of me!”   
Edge only responded by wrapping an arm around Sci, before he suddenly kissed him. Sci froze his eyes widening a little. He knew he should stop him, but let's face it nearly everyone knew his feelings for Edge so he was tempted to let the other do whatever he wanted.  
Edge flipped their position, breaking the kiss. This gave Sci a moment of clarity, “W-wait, Edge, you're drunk. You’ll regret this later.”  
“Nah,” the other simply responded before he leaned down and attacked Sci’s neck.   
Sci shivered as the kisses became sloppy and wet. His eyelids drifting a bit. When the other’s knee was pressed to his groin, he gasped.  
Edge chuckled, “Now ya know how it feels~”  
Sci’s eyelids fluttered a little, as he felt the other rub his groin. Edge continued to leave sloppy kisses along his neck.  
“Fuh… Edge…”  
Edge suddenly bit into the area.  
“God! Fuck!”  
Edge grinned before he licked over the mark he made.  
“So… good…”   
“Really cuz I’m just getting started~” Edge pulled back, leaning into kiss the other again. Sci gave a soft hum as he kissed back, wrapping his arms around the other’s neck. He felt Edge smirk against his lips, he had no time to react before the other repressed his knee against his crotch and began to rub the area again.   
Sci gasped into the kiss, allowing Edge to slip his tongue in. Oh god was his own tongue that long? Sci didn’t even bother attempting to dominate the kiss. He let out a soft suppressed moan. Edge pressed further into the kiss and bit his lower lip. Sci arched slightly into the new feeling, pressing himself a little uncomfortably against Edge’s knee. Feels so good.  
Sci bucked into the other, he needed more friction. He moaned, feeling Edge’s right hand begin to feel up his shirt. Edge pulled back to catch his breath as his fingers found the other’s left nipple, tweaking it a bit.  
“Fuck…”  
Fuck indeed, especially in Edge’s drunken state. Neither had shed an article of clothing, aside from their jackets when they first got in the room, and this was still a sight to see:  
Sci trying to keep in as many lewd sounds as possible as Edge’s hand played with the nipple under his shirt and he pretty much tried to fuck himself against Edge’s knee.   
Edge really wanted to go for the bit of skin shown from the other’s shirt being lifted, but he was just sober enough to remember he wasn’t really flexible.  
His eyes drifted from the area when he heard the other gasp his name.  
“E-edge, fuck, I think we’re wearing too much…”   
“Why don’t ya do someth’n about it then?” Edge smirked.  
“Drunk and still as much of a dick,” Sci grumbled, a blush flooding his cheeks.  
He shoved Edge off of him, the other chuckled, “Geez, don’t be such a drag, Bud.”  
When the pun registered Sci laughed a bit, “Sorry, Chaser, but I’m a bit impatient.”  
Edge gripped Sci’s shirt and pulled him into a quick kiss.   
Once they pulled away each made quick work of their clothes. Sci gasped when he was practically thrown back into the bed, a red glow around him. “C-careful!”  
“Don’t be such a big baby, there was no intention of harm behind it. You’re 1 HP is fine,” Edge rolled his eyes.  
“You’re drunk, you don’t have complete control over your magic!”   
When did he get so whiny? Or was angry the better word? Edge wondered. “Sorry?”  
“Just… just don’t use your magic this time.”  
Edge found himself grinning, “This time?”  
“Shut up,” Sci pulled Edge down into him and into a kiss.  
Edge chuckled, he certainly wasn’t going to complain about this new side of Sci.  
Sci felt himself mellow once their lips connected. He really had no clue why he just snapped like that since he knew Edge was just messing with him.   
Maybe this was what Ink tried to warn him about?  
His train of thought vanish when he felt Edge’s hand wrap around him.  
~~~~  
“Sci… Sci. Come on, Buddy. Wake up!”  
Sci rolled away from the voice and the hand shaking him, curling against Edge.  
“I know you're awake. This is serious.”  
When Sci refused, he felt something soft against his nose. He shot his hand over his face, keeping his voice low, “Fine... Fine. I’m up.”  
He sat up, feeling a little disappointed, there was only one reason why he would be here.  
“I thought I had a few more days,” He blinked, “Did something happen? Is Grillby having some issue with Papyrus?”  
The other chuckled, “No. No. Papyrus is fine. It's just… I need to take you home.”  
“Why?”  
“Please, Sci. Trust me,” Sci noticed the other’s eyes change. He couldn’t really describe the symbols. The emotion was clear: concern.  
“Fine… Can I at least have a few minutes to wake Edge up and say goodbye?” Sci asked.  
The other nodded, his hair falling in his face, “Of course.”  
There was the star of happiness.  
“Thanks, Ink.”  
Ink smiled before taking out his paintbrush and painting a dark spot on the floor, “Jump on through when you’re ready.”  
The artist hopped into the puddle. Sci didn’t bother trying to figure out how exactly that worked.  
Sci reluctantly got off of the bed, he grabbed his clothes from a few hours before and dressed. He crossed the room to grab his coat.  
“Was I that bad?”   
Sci froze, a blush crawling over his face.  
Edge chuckled, “Seriously though, where are you going?”  
Sci gripped his coat in his right hand and adjusted his glasses with his left, “Ink was just here. I, uh, I need to to go. Something seems to be wrong.”  
“Oh and you were just goin' to leave?”   
“No,” Sci turned around, seeing Edge was sitting up, blanket on the other side of the bed. Sci bit his lip and looked away, blushing.  
“Weirdo,” Edge smirked.  
Sci frowned, “Says the self-fucker.”  
“Oo and he comes back with a bone to pick,” Edge chuckled.  
“And I have a skele-ton more japes to throw back, if you think you can handle them,” Sci crossed his arms, eyebrow cocked.  
“I think I’ve handled ya just fine until now.”  
Sci chuckled, then sighed, “I’d love to continue this but Ink was pretty serious…”  
“Can I at least get a goodbye kiss?” Edge smirked.  
“That depends on where you're wanting that kiss because there won’t be any sucking,” Sci said.  
Edge chuckled, “I wasn’t leading to that but if you want to~”  
Sci let out a playful scoff, “What kind of sinner do you take me for?” He crossed over the room, stepping passed the portal; he sat on the bed leaning in to kiss the other, Edge met him halfway.  
Sci smiled as he felt Edge’s arms circle him and pull him closer, he let out a soft moan then felt something shove into his back and pulled out of the kiss and glared behind him just in time to see the handle of a large paintbrush disappear into the portal.  
Edge sighed, “See you around, Nerd...”  
Sci got off the bed and fixed his glasses, “I’ll try to convince Ink to let me come back soon,” he smiled  
He watched Edge smile back before he jumped through, landing outside his own home in Snowdin. Before he could say anything to the artist Ink said, “Give it a few weeks, okay? You’ll start feeling like you again and I’ll send you back for a bit or I might bring him here.”  
“Feeling like me?” Sci asked, confused.  
“Just try not to get irritated with Papyrus when he asks you a thousand questions about your sleepover in Underfell, okay?” Ink smiled before swiping his paintbrush on the ground and jumping through.  
Sci shook his head and took a shortcut to his room, once inside he took off his lab coat and realized he was wearing Edge’s clothes. He grinned, there was no way he was getting them back without coming for them.


End file.
